1. Field of the Invention
The present invention relates to control of the flow of liquid and gas after their separation to maintain their separation by providing a flow path for the liquids which militate against reentrainment of the liquids by the gas. More specifically, liquid initially separated from gas in which the liquid has been entrained is flowed downward over a surface upon which the gas and liquid impinge and along a mechanically provided path in isolation from the separated gas.
2. Description of the Prior Art
There are many configurations of baffles mounted in vessels which provide surfaces promoting separation of liquid and gas mixtures passed through the vessels. The vessels are usually cylindrical because this form of vessel is generally simple and relatively inexpensive to manufacture. When expanded capacity must be accommodated, the vessels may be extended vertically and/or their diameter increased.
One of the most effective techniques of separation is to impinge the mixture upon a baffle surface and then flow the liquid down along this surface to join a lower collection of the liquid from which the liquid can be drawn from the vessel in separation from the gas. To bring about liquid impingement, mixtures have been given a circular flow path to generate centrifugal force upon the liquid which will move the liquid into baffle surface contact. Generally, centrifugal force has been generated in vertical vessels in which vertical baffles are mounted. However, in at least one part of these flow paths, there remains a maximum likelihood of reentrainment of the liquid by the gas. Where the liquid impinged on a baffle mechanically disengages therefrom and falls to a lower collection of liquids, direction must be given the falling separated liquid which will obviate reentrainment.
In the system disclosed in my U.S. Pat. No. Lowery 3,877,904 dated Apr. 15, 1975, I provided for part of the separated gas to force separated liquid falling from the lower edge of a baffle surface into a path which would avoid reentrainment by the major portion of the separated gas. Specifically, I provided a perforated horizontal plate traverse the vertical shell sized to be smaller than the internal wall of the vessel. I thus provided a path for part of the separated gas to sweep the liquid drops falling from the edge of the upper baffle surface. The falling drops were swept around the edge of the plate and subsequently disengaged from the small portion of the separated gas to fall into the separated liquids below. The small portion of the separated gas disengaged from the liquid and then flowed upward through the perforations of the horizontal plate and out the vessel with the remaining separated gas.
Experience subsequent to the development of the system of my U.S. Pat. No. 3,877,904 has shown further direction must be provided for the descending liquid drops on the baffle surface. It became evident that a mechanical provision was required to direct liquid from the lower edge of the baffle surface to the separated liquid on the internal wall of the vessel.